Method for improving a fluid dynamic profile of a marine vessel, a marine vessel having an improved fluid dynamic profile, and a coating system for improving the fluid dynamic profile

Abstract

A method for improving a fluid dynamic profile and fouling properties of a marine vessel with a welding seam which forms a cap protruding above a surface being under the waterline of a vessel. The method comprising amending the welding seam by applying a fairing to the underwater surface, e.g. by use of filler. A vessel with a fairing, and a coating system for a vessel and including a fairing.

The invention claimed is: 
     
       1. A method for improving a fluid dynamic profile of a marine vessel, the method comprising the step of identifying at least one welding seam forming a cap protruding above an underwater surface of the marine vessel, and amending a profile of the marine vessel by applying a fairing to the underwater surface and to the at least one welding seam,
 wherein the fairing is applied to the underwater surface and to the at least one welding seam by applying unsolidified filler to the underwater surface and to the at least one welding seam, shaping the filler, and solidifying the filler. 
 
     
     
       2. The method according to  claim 1 , wherein the unsolidified filler is applied from a pump into an application tool configured to be moved over the underwater surface and configured to define a shape of the fairing. 
     
     
       3. The method of  claim 1 , comprising the step of applying a fairing having a triangular shape forming a lower surface against the underwater surface and two top surfaces extending from a top point above the at least one welding seam and sloping from that top point downwards towards the lower surface. 
     
     
       4. The method of  claim 3 , comprising the step of applying a fairing having the shape of an isosceles triangle. 
     
     
       5. The method according to  claim 1 , wherein the fairing is applied to cover the at least one welding seam and a heat affected zone (HAZ) of the at least one welding seam. 
     
     
       6. The method according to  claim 1 , wherein the fairing is applied symmetrically about the at least one welding seam. 
     
     
       7. The method according to  claim 1 , wherein the fairing is applied over the at least one welding seam between a primer layer and a topcoat. 
     
     
       8. The method according to  claim 1 , wherein the fairing is covered with a fouling control surface coating system. 
     
     
       9. The method according to  claim 1 , comprising identifying at least one longitudinal welding seam extending on the underwater surface in a longitudinal direction in which the marine vessel is designed to sail, identifying at least one transverse welding seam extending on the underwater surface in a transverse direction being transverse to the longitudinal direction, and applying the fairing to the at least one transverse welding seam without applying a fairing to the at least one longitudinal welding seam. 
     
     
       10. The method according to  claim 9 , wherein the fairing is applied exclusively to at least one welding seam extending in a direction being perpendicular to the longitudinal direction. 
     
     
       11. The method according to  claim 1 , wherein the fairing is applied only on a downstream side of the at least one welding seam facing backwards relative to a sailing direction of the marine vessel. 
     
     
       12. The method according to  claim 1 , wherein the fairing is applied at most on at least one welding seam in a forward half part of the underwater surface of the marine vessel, the forward half part of the underwater surface extending from a front end pointing forward the sailing direction and half the way towards a rear end of the marine vessel. 
     
     
       13. The method according to  claim 1 , wherein the marine vessel is operated with a speed through water with the fairing applied to the underwater surface and at least one welding seam. 
     
     
       14. A marine vessel having a hull forming a welding seam extending along an underwater surface and forming a cap projecting a seam-height in an outwards direction away from the underwater surface, the marine vessel further comprising a fairing extending in an axial direction and projecting a fairing-height in the outwards direction and covering at least a part of the welding seam and underwater surface. 
     
     
       15. The marine vessel according to  claim 14 , wherein the fairing-height decreases in a width direction along the underwater surface away from the welding seam. 
     
     
       16. The marine vessel according to  claim 14 , wherein the fairing-height is between 90 and 110 percent of the seam-height. 
     
     
       17. The marine vessel according to  claim 14 , wherein the fairing terminates in two side edges extending in the axial direction on opposite sides of the welding seam. 
     
     
       18. A The marine vessel according to  claim 17 , wherein at least one of the side edges extends at a distance of at least 5 times the fairing-height from the welding seam. 
     
     
       19. The marine vessel according to  claim 17 , wherein the distance from one side edge to the welding seam equals the distance from the other side edge to the welding seam. 
     
     
       20. The marine vessel according to  claim 14 , wherein the fairing has an outer surface facing away from the underwater surface, the outer surface being convex in a cross-section transverse to the axial direction. 
     
     
       21. A coating system for an underwater surface of a marine vessel, the coating system comprising at least one layer of a primer applied to the underwater surface, a fairing configured to amend the profile of the underwater-surface at a welding seam and applied in accordance with  claim 1 , the fairing being applied to the primer, and a top coat applied to the fairing. 
     
     
       22. The coating system according to  claim 21 , further comprising a layer of a tie-coat applied between the fairing and the top coat. 
     
     
       23. The coating system according to  claim 21 , wherein the top coat comprises at least one layer of a fouling control surface coating system.